audio: Deprecate Update

audio/audio.go

@@ -43,6 +43,7 @@ import (
 
 	"github.com/hajimehoshi/oto"
 
+	"github.com/hajimehoshi/ebiten/internal/audiobinding"
 	"github.com/hajimehoshi/ebiten/internal/clock"
 )
 
@@ -180,7 +181,6 @@ func (p *players) hasSource(src ReadSeekCloser) bool {
 //    }
 type Context struct {
 	players        *players
-	errCh          chan error
 	initCh         chan struct{}
 	initedCh       chan struct{}
 	pingCount      int
@@ -216,7 +216,6 @@ func NewContext(sampleRate int) (*Context, error) {
 	}
 	c := &Context{
 		sampleRate: sampleRate,
-		errCh:      make(chan error, 1),
 	}
 	theContext = c
 	c.players = &players{
@@ -266,7 +265,7 @@ func (c *Context) loop() {
 
 	p, err := oto.NewPlayer(c.sampleRate, channelNum, bytesPerSample, c.bufferSize())
 	if err != nil {
-		c.errCh <- err
+		audiobinding.SetError(err)
 		return
 	}
 	defer p.Close()
@@ -290,26 +289,21 @@ func (c *Context) loop() {
 		c.writtenBytes += l
 		buf := make([]uint8, l)
 		if _, err := io.ReadFull(c.players, buf); err != nil {
-			c.errCh <- err
+			audiobinding.SetError(err)
+			return
 		}
 		if _, err = p.Write(buf); err != nil {
-			c.errCh <- err
+			audiobinding.SetError(err)
+			return
 		}
 	}
 }
 
-// Update returns an error if some errors happen, or nil if there is no error.
+// Update is deprecated as of 1.6.0-alpha.
 //
-// As of 1.6.0-alpha, Update just returns the error if an error happens internally,
-// and do nothing related to updating the state.
-// Then, the audio is available without Update,
-// but it is recommended to call Update every frame to check errors.
+// As of 1.6.0-alpha, Update always returns nil and does nothing related to updating the state.
+// The internal audio error is returned at ebiten.Run instead.
 func (c *Context) Update() error {
-	select {
-	case err := <-c.errCh:
-		return err
-	default:
-	}
 	return nil
 }
 

internal/audiobinding/error.go

@@ -0,0 +1,25 @@
+// Copyright 2017 The Ebiten Authors
+//
+// Licensed under the Apache License, Version 2.0 (the "License");
+// you may not use this file except in compliance with the License.
+// You may obtain a copy of the License at
+//
+//     http://www.apache.org/licenses/LICENSE-2.0
+//
+// Unless required by applicable law or agreed to in writing, software
+// distributed under the License is distributed on an "AS IS" BASIS,
+// WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+// See the License for the specific language governing permissions and
+// limitations under the License.
+
+package audiobinding
+
+var ch = make(chan error, 1)
+
+func Error() <-chan error {
+	return ch
+}
+
+func SetError(err error) {
+	ch <- err
+}

run.go

@@ -18,6 +18,7 @@ import (
 	"image"
 	"sync/atomic"
 
+	"github.com/hajimehoshi/ebiten/internal/audiobinding"
 	"github.com/hajimehoshi/ebiten/internal/clock"
 	"github.com/hajimehoshi/ebiten/internal/ui"
 )
@@ -79,6 +80,11 @@ func (u *updater) SetSize(width, height int, scale float64) {
 }
 
 func (u *updater) Update(afterFrameUpdate func()) error {
+	select {
+	case err := <-audiobinding.Error():
+		return err
+	default:
+	}
 	n := clock.Update()
 	if err := u.g.Update(n, afterFrameUpdate); err != nil {
 		return err
@@ -108,8 +114,8 @@ func (u *updater) Invalidate() {
 //
 // The given scale is ignored on fullscreen mode.
 //
-// Run returns error when 1) OpenGL error happens, or 2) f returns error.
-// In the case of 2), Run returns the same error.
+// Run returns error when 1) OpenGL error happens, 2) audio error happens or 3) f returns error.
+// In the case of 3), Run returns the same error.
 //
 // The size unit is device-independent pixel.
 //